Heat insulating cylinder for thermal treatment of semiconductor wafers



FIG. 1 is a front elevational view of a heat insulating cylinder for thermal treatment of semiconductor wafers showing our new design;

FIG. 2 is a right side elevational view, the left side elevational view being a mirror image;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view; and,

FIG. 5 is a rear elevational view thereof. 

The ornamental design for a heat insulating cylinder for thermal treatment of semiconductor wafers, as shown and described. 